Thanasi Kokkinakis hopes his turbo-charged US Open triumph over Stefanos Tsitsipas will be the spark that finally gets his faltering career back on track.

The hapless South Australian rightly described his 7-6 (7-5), 4-6, 6-3, 7-5 victory over the 11th seed at the Open and two-time Grand Slam finalist as his best victory at a major to date.

“A huge relief,” said Kokkinakis after knocking out last year’s Australian Open finalist to claim only his second US Open main draw victory.

“Super happy. Super excited. It’s well documented that I’ve had some close games, but now I’m starting to win them.

“It’s just a lot of hard work, staying positive and working my ass off.”

But the former Roger Federer conqueror admits that reaching the US Open junior final 11 years ago feels like an eternity, and now that he is finally injury-free, he says it is high time to realise his undisputed potential.

“It happened quickly,” said Kokkinakis.

“There was this interim period of five or six years in my career where I basically didn’t show up, tried to come back but couldn’t.

“I never felt like I played my best tennis here, which is surprising because it should suit me and my game.

“But I trained well and was able to play (today) fairly close to my training level.”

Some of his best years were taken away from him and he has had a difficult time since having shoulder surgery on his right serving arm at Christmas 2015.

Since then, he has suffered from elbow and knee injuries, persistent pubic bone inflammation, chest problems, and tears in the oblique and abdominal muscles.

“One of my main goals is to make the most of what I have left,” said the 28-year-old.

“I missed the middle phase of my career. When you’re younger and you’re shooting up the rankings pretty quickly, you think it’s over.”

Kokkinakis knows that eliminating Tsitsipas will do him little good unless he can repeat his win over world number 34 Nuno Borges and advance to the third round and beyond.

“A lot of the impressiveness of these guys is down to their consistency in performing week after week and giving themselves chances to play,” he said.

“I always knew I was capable of beating good top 10 players, I have already proven that.

“It’s just about being consistent.”

AUSSIES IN ACTION ON DAY THREE OF THE US OPEN ON WEDNESDAY (THURSDAY AEST):

Men’s singles, second round

28 – Alexei Popyrin vs Pedro Martinez (ESP)

Rinky Hijikata vs Grigor Dimitrov (BUL)

Women’s singles, second round

Maya Joint vs. 14-Madison Keys (USA)

Ajla Tomljanovic against 33-Elise Mertens (BEL)